'''
def sum_num(a,b):
    return a+b
result=sum_num(1,2)
print(result)

#交换数值
a,b=1,2
a,b=b,a
print(a)
print(b)
'''
#引用之不可变类型
#id指明内存地址
a=1
b=a
print(b)
print(id(a))
print(id(b))

a=2
print(b)
print(id(a))
print(id(b))